Fluid heat transfer system



May 25, 1965 w. H. NEBGEN FLUID HEAT TRANSFER SYSTEM 5 Sheets-Sheet 1 Filed April 22 1963 INVENTOR. MAL/14f) H Nessa/v l'OPA E/ y 5, 1965 w. H. NEBGEN 3,185,212

FLUID HEAT TRANSFER SYSTEM Filed April.22, 1963 3 Sheets-Sheet 5 Z4 INVENTOR. h/ILLl/IM H. #5560! M); I AZWEXS;

United States Patent 3,185,212 FLUID HEAT TRANSFER SYSTEM William H. Nebgen, Woodside, N.Y., assignor of two-fifths to Frank A. Howard, New York, Nfifi; Erma Arne-ha Howard, Frank A. Howard, lira, and The (Ihase Manhattan Bank, executors of said Frank A. Howard, deceased Filed Apr. 22, 1963, Ser. No. 274,679 14 Claims. (Cl. 165-86) In my prior applications Serial No. 148,920, filed October 31, 1961, and Serial No. 200,116, filed June 5, 1962, both now abandoned, I have shown and described fluid heat transfer systems in which certa'm special forms of rotary motions, either a combined orbital and planetary rotation, or a simple gyratory motion, of a liquidretaining wall of circular cross section, such as conventional tube, is used to keep wetted the entire inner surface of the wall without filling the enclosed cross section with the liquid, this resulting both in increasing the exposed surface of the contained liquid and permitting an increase in the rate of heat transfer through the wall. This apparatus and method of operation is widely useful as a means of improving the rate of heat transfer between fluids in many types of industrial facilities including those for recovery of fresh water from saline water by distillation procedures and is also especially adapted for use in cooling recirculated water which is to be used for heat exchange purposesby evaporating some portion of the recirculated stream into an air current, and has even further advantages where a vapor is to be simultaneously condensed on [the outer'surface of the liquidretaining wall as in the case of an evaporative condenser. For such purposes there may be employed the simplified design of the present invention.

This invention will be fully understood from the accompanying specifications taken in connection with the annexed drawings in which FIGURE 1 is a diagrammatic and partly fragmentary vertical cross section through an evaporative condenser embodying my invention, FIG- URE 2 is a diagrammatic top plan view of the structure illustrated in FIGURE 1 with part of the upper frame and the water chest removed, and FIGURE 3 is an enlarged vertical section of the right hand upper portion of FIGURE 1.

In these drawings there is shown fragmentarily a stationary structural steel frame which supports a self-contained evaporative condenser which takes the general form of a movable assembly carried on stationary supports and'including vertical heat-exchange tubes mounted in a relatively short annular shell which is suspended from the stationary frame by hangers which permit the desired relative gyratory motion which is set up by means of a central shaft mounted in the frame and carrying eccentrics which cause the assembly to gyrate on a relatively short radius around the axis of the shaft. The same central shaft may carry the fans by which air is drawn through the apparatus and the counterweights by which the gyrating assembly is counterbalanced. With the use of a self-contained structure of this kind it is possible to provide for the condensation of a vapor such, for example, as a refrigerating fluid vapor of the halogensubstituted hydrocarbon type, by transfer of the heat of condensation to water passing down through the insides of the tubes, the water itself being simultaneously cooled by evaporation in part into an air current moving through the tubes in contact with the exposed water surfaces.

The specific construction illustratedin the drawings comprises a stationary structural steel frame 15 supporting a relatively short annular shell-and-tube heat-exchange assembly having an outer shell ring 1 and an inner shell ring 2, the heads 4 closing the annular space 3,185,212 Patented May 25, 1965 ICC between these two shell rings carrying the closely spaced vertical heat-exchange tubes 3. Upper and lower stiff spiders 5 which transmit the gyratory motion to the shell i V the fans '7 which are mounted on the central shaft 16.

Each fan may carry a light crescent-shaped shroud 8 on on the side opposite a counterweight 9 which is supported by the radial arm 16 from the fan hub. The heavy central spider 12 extends between the inner shell ring 2 and the shaft 16 and may carry vertical webs 11 which also serve as straightening vanes. The shaft 16 carries three eccentrics, the top and bottom eccentrics being designated 13 and the center eccentric 14. These eccentrics rotate in radial bearings carried by the spiders 5 and 12. The central shaft 16 which carries the eccentrics, fan-wheels and counterweights is supported at the bottom on thrust and radial bearings 17 and 18 and. is driven through suitable gears in the gear case 19, from an electric motor 20.

The lower end of the condenser shell is closed by a half-torus 21, the radially outward portion of which has a spaced outer cover 22 which collects the water from the inside of the torus thourgh drain holes 23. To supply the vapor to be condensed to the shell 1 there is required a large flexible pip-e connection such as is shown at 24, this same connection being of sufficient cross secrtion so that the condensate may also return by gravity to the condensate trap, as indicated by the arrows.

Surmounting the shell and carried by it there is a water inlet chest 25 having a flexible connection 26 to the stationary recirculating water pipe which is shown as supported by an angle iron 30 forming a part of the stationary frame. A fixed top bearing 27 for the upper end of the shaft is supported by an upper structural steel member 28 also forming a part of [the stationary frame. The shell of the condenser is supported from the top frame member 34) by means of a number of hanger rods 2? which are fastened at their lower ends in a channel iron 36 which surrounds the midsection of the shell. The rods 29 may be loosely-secured simple tension members, but if desired they may be flexible enough to permit them to be rigidly fastened both to the frame member 30 and to the channel ring 36 and still permit the short-radius gyratory movement. Flexible outlet connections 31 for the recirculated water are connected to a pump, not shown, by which this recirculated stream, along with any necessary makeup water, is delivered to the water inlet chest 25. From this annular water chest, superimposed above the shell, the water is delivered by small individual nozzle pipes 32 to the top of each of the evaporator tubes 3. A flexible connection 33 is interposed between each water delivery nozzle 32 and the water chest 25, so that the nozzles 32 are free to swing under the influence of the gyratory force so as to remain always in contact with that portion of the inner wall of the tube 3 most distant from the axis of the shaft 1 6. The gyrating radius of the structure is indicated'at 34 in FIGURE 2, being the distance between the axis of the shaft 16 and the axis of the eccentrics 13. I

The operation of the gyratory evaporative condenser, above shown and described, may be summarized as fol: lows. The driving motor 29, operating through the gear box 19, rotates the central shaft 16 at a speed suflicient to create the desired centrifugal force in the moving assembly, this force obviously depending upon the angular velocity of the shaft and the radius of'gy-ration 34. Because of bearing friction the rotation of the shaft 16 has a slight tendency to drag the shell around with it in the same direction, but this simple rotational movement of the shell may be adequately resisted both by the flexible fluid connections 24 and 26 and also by the inherent geometry of the suspension arrangements, supplemented by the stiffness of the suspension rods 29 if these are rigidly secured at each end. Being unable to rotate as a whole, the shell moves in a gyratory path on the radius 34; that is to say each point in the assembly tends to rotate in a horizontal plane on this same radius. Such motion may be further ensured by an accordionlike structure made up of a plurality of concentric flexible sheet steel rings of varying diameters, joined alternately at the top and bottom edges, interposed in a conical series between the central hub of the upper spider and the stationary frame member 29. This accordionlike flexible ring structure shown at 37 in FIGURES 1 and 3 permits the upper spider 5 and the shell to which it is attached to gyrate quite freely on the short radius 34, the flexible sheet steel rings bending sufiiciently for this motion, but since each ring is substantially cylindrical the resistance to any relative torsional movement is very high. The maximum possible relative rotation of the shell to the frame .is, therefore, negligible and the desired pure gyratory motion of the shell is ensured quite independently of any other resistance to rotation.

As described in my earlier application referred to, a positive gyratory motion can be most readily Visualized as accomplished by mounting the body to be gyrated on a connecting rod joining parallel cranks of equal radius, this construction permittingno possibility of deviation from the desired motion. For present purposes, however, the desired gyratory motion of the evaporative condenser assembly as a whole may be adequately ensured by the simplified arrangements above described. As, in the case of the structures shown in my earlier applications this simplified design causes the partially filled liquid conduit to rotate bodily in a plane perpendicular to its axis to develop centrifugal force causing the liquid stream to remain in the radially outward part of the cross section of the. conduit while simultaneously rotating the conduit with respect to its own axis to bring theunsubmerged portions of the inner surface of the conduit progressively under the liquid stream.

The same rotation of the shaft 16 which produces the gyratory motion of the shell drives the propeller fans 7 which in the designdllustrated pull air downwardly through the tubes 3 and upwardly through the center of the shell, the diffuser or straightener vanes 6 and 11 assisting in maintaining the desired axial air flow through the center of the shell with minimum turbulence. To increase fan eflficiency each fan wheel may carry a crescent-shaped shroud 8 to blank the open crescent space on the side toward the axis of the eccentrics 13. On the opposite side, each-fan wheel may conveniently carry a counterweight -9 of mass suflicient so that its moment of rotation exactly balances the moment of the shroudsand of the gyrating mass of the assembly at the designed speed. If the radius at which the countersupporting arms 10, is greatly in excess of the radius of gyration, as is here shown, the required mass of the counterweights may be very small as compared with the mass of the moving assembly. These arrangements determined by the size .of the nozzle outlets and the.

head, to the top of each'one of the tubes 3,. and the gyratory motion of the shell, including. that of the water chest 25 which it carries, will cause the water delivery nozzles 32 to swingoutwardly and circle around the insides of the tubes so as to contact always that side of weights 9v move, as determined by the length of their each tube 3 in which a segmental-shaped pool of the water delivered from the nozzle tends to collect by reason of the same centrifugal force. Under'the influence of gravity any such water pool will follow a helical path downward through each tube 3, making one turn for each gyration of the shell and thus keeping the entire tube surface wetted While leaving the center of the tube free for the down-passage of air. Assuming that vapors of a refrigeration fluid, suchas one of the halogensubstituted hydrocarbons commonly used in air conditioning installations, is simultaneously supplied to the shell of the condenser through the flexible connection 24, these vapors will condense upon the outer surfaces of the tubes 3, keeping these surfaces. continuously-wetted by a film of condensate but preventing any accumulation of liquid thereon, since the centrifugal force created by the gyratory motion will dislodgecontinuously any liquid which would otherwise accumulate in appreciable thickness on the outer surfaces of the tubes. The liquid condensate will, however, under the influence of gravity, descend to the base of the shell from whence it may flow to the condensate trap through the same flexible connection 24 through which the vapors entered.v Although in the drawings I have illustrated only a single flexible inlet. 24 for vapors and inlet 26 for water, it will be understood that it is desirable to use at least two of such connections, arranged symmetrically so that any resistance they offer will be balanced and will not tend to disturb the gyratory motion of the partsof the assembly to which they are attached. It will be noted that: the half-torus 21 which closes the bottom of the shell provides an eflective separator, the water tending to collect somewhat toward the outside of the torus and being drained. outwardly through the openings 23 while the accompanyingair stream is turned at by the smooth curve of the torus so that it is directed upwardly through the center of the shell with the minimum unnecessary turbulence. V

. 'Since the entire inner surfaces of the tubes 3 are kept wetted by a constantly renewed film of water created by the helical descending streamdelivered into each tube through its inlet nozzle 32, there is the maximum opportunity for evaporation of this Water into the air current passing downwardly through a very large part of the cross section of each tube. The construction shown and described, operating as a simple evaporative' cooler for recirculated water is, therefore, highly economical and efiicient, whether the air stream moves concurrently with'the Water or countercurrent thereto, this choice depending upon the. specific conditions. When used as an evaporative condenser for a refrigerating fluid in the manner described, the concurrent flow of water'and air through the tubes may be preferred, and as heretofore stated the entire outer surfaces of all tubes 3 may be kept Wet by condensation but there can be no accumulation of liquid droplets or appreciable. thickness of a liquid layer on these outer surfaces to retardtransfer of heat, all such accumulations being prevented by the gyratory motion which may create forces many times as great asthat of gravity to dislodge any liquid accumulations.

While I have shown and described in considerable detail one specific embodiment of my invention, together with some possible modifications thereof, it will ,be understood that this is only for the purpose of making the invention more clear and that I do not regard it as limited save by the terms of the appended claims in -which it is my intention to claim all novelty inherent in thisinvention as broadly as ispermissible in view of' the prior art.

. What I claim is:

the assembly, eccentric bearings between the shaft and the assembly, liquid conduits of circular cross section carried by the assembly with their axes remote from and parallel with the shaft, means for introducing liquid into one end of such conduits and means for withdrawing it at the other end at a rate to prevent the conduits from filling with liquid, means for passing another fluid through the assembly in heat exchange relation to the liquid flowing through the conduits, connections between the assembly and the support for preventing rotation of the assembly around its own axis while permitting the assembly to gyrate with respect to its support, and means for rotating the shaft at a rate to set up centrifugal forces resulting from the gyratory motion to control the movement of liquid bodies contained in such partially filled conduits.

2. An apparatus as defined in claim 1 in which the ends of the conduits which receive the liquid are above their exit ends, so that the force of gravity may combine with centrifugal force to cause helical downward movement of the liquid bodies through the partially filled conduits.

3. An apparatus as defined in claim 1 in which the means for delivering another fluid comprises gaseous fluid connections for the inlet and outlet ends of the liquid conduits, and means for forcibly moving a gaseous fluid through the open space in said partially filled conduits.

4. An apparatus as defined in claim 1 in which the assembly includes a shell which forms a closed chamber surrounding the liquid conduits and the means for delivering another fluid comprises fluid connections with such closed chamber.

5. An apparatus as defined in claim 3 in which the assembly includes a shell which forms a closed chamber surrounding the liquid conduits and the means for deliven'ng still another fluid comprises fluid connections with such closed chamber.

6. An apparatus as defined in claim 2 in which the assembly is suspended from the stationary support by relatively long tension members having suflicient freedom of motion to permit the gyration of the assembly.

7. An apparatus as defined in claim 1 in which the assembly is connected with the stationary support by an accordion-like structure made up of a series of concentric rings of increasing diameter connected alternately at their upper and lower edges so as to permit relatively free motion of gyration between the shell and its stationary support while strongly resisting any relative motion of rotation.

8. An apparatus in accordance with claim 1 in which the assembly includes an annular shell which provides a large central axial passage, and a fan is located within said passage for moving gaseous fluid therethrough.

9. An apparatus in accordance with claim 1 in which the shaft carries a counterweight to balance the gyrating mass of the assembly.

10. An apparatus in accordance with claim 2 in which the means for introducing liquid into the upper end of the conduits comprises a separate delivery nozzle for each conduit, flexibly suspended from a liquid supply connection and entering the upper end of the liquid conduit so that centrifugal force will determine its point of contact with the inner surface of the conduit.

11. An apparatus for fluid heat transfer comprising a liquid conduit of generally circular cross section, means for supplying liquid to one end and withdrawing it from the other end at a rate to maintain the conduit only partially filled, means for rotating the conduit bodily in a plane perpendicular to its axis around a center remote from such axis to develop centrifugal force causing the liquid stream to remain in the radially outward part of the cross section of the conduit and for simultaneously causing the conduit to rotate with respect to its own axis so as to bring the unsubmerged parts of the inner surface of the conduit progressively into contact with the liquid stream, and means for passing a second fluid over the surface of said conduit for exchange of heat with the liquid.

12. An apparatus as defined in claim 11 in which the conduit is formed of a heat-conducting material and enclosed in an outer chamber provided with connections for supply and withdrawal of a second fluid which may thus be brought into indirect heat exchange relation with the liquid passing through the conduit.

13. An apparatus as defined in claim 11 including connections to the ends of the liquid conduit and means for passing a gaseous fluid through said conduit simultaneously with the passage of the liquid therethrough to obtain heat exchange between said gaseous fluid, the surface of the liquid stream and the unsubmerged wet surface of the conduit.

14. An apparatus as defined in claim 11 in which the conduit is formed of a heat-conducting material and enclosed in an outer chamber provided with connections for supply and withdrawal of a second fluid which may thus be brought into indirect heat exchange relation with the liquid passing through the conduit, and which includes connections to the ends of the liquid conduit and means for passing a gaseous fluid through said conduit simultaneously with the passage of liquid therethrough to obtain heat exchange between said gaseous fluid, the surface of the liquid stream and the unsubmerged wet surface of the conduit.

References Cited by the Examiner UNITED STATES PATENTS 1,428,557 9/22 Ray et a1 108 X 2,106,295 1/38 Cook 165--108 X 2,468,903 5/49 Villiger 165-160 X 2,577,856 12/51 Nelson 165108 X FOREIGN PATENTS 11,268 8/88 Great Britain.

CHARLES SUKALO, Primary Examiner. FREDERICK L. MATTESON, JR., Examiner. 

1. AN APPARATUS FOR THE EXCHANGE OF HEAT BETWEEN TWO FLUIDS COMPRISING A STATIONARY SUPPORT CARRYING A MOVABLE HEAT EXCHANGER ASSEMBLY, A SHAFT HAVING AN AXIS FIXED WITH RESPECT TO THE SUPPORT AND PASSING CENTRALLY THROUGH THE ASSEMBLY, ECCENTRIC BEARINGS BETWEEN THE SHAFT AND THE ASSEMBLY, LIQUID CONDUITS OF CIRCULAR CROSS SECTION CARRIED BY THE ASSEMBLY WITH THEIR AXES REMOTE FROM SAID PARALLEL WITH THE SHAFT, MEANS FOR INTRODUCING LIQUID INTO ONE END OF SUCH CONDUITS AND MEANS FOR WITHDRAWING IT AT THE OTHER END AT A RATE TO PREVENT THE CONDUITS FROM FILLING WITH LIQUID, MEANS FOR PASSING ANOTHER FLUID THROUGH THE ASSEMBLY IN HEAT EXCHANGE RELATION TO THE LIQUID FLOWING THROUGH THE CONDUITS, CONNECTIONS BETWEEN THE ASSEMBLY AND THE SUPPORT FOR PREVENTING ROTATION OF THE ASSEMBLY AROUND ITS OWN AXIS WHILE PERMITTING THE ASSEMBLY TO GYRATE WITH RESPECT TO ITS SUPPORT, AND MEANS FOR ROTATING THE SHAFT AT A RATE TO SET UP CENTRIFUGAL FORCES RESULTING FROM THE GYRATORY MOTION TO CONTROL THE MOVEMENT OF LIQUID BODIES CONTAINED IN SUCH PARTIALLY FILLED CONDUITS. 